forteh Posted May 25, 2013 Report Share Posted May 25, 2013 (edited) Having invested in a decent full sus frame (intense 5.5) and a reverb, I'm slowly moving my bike into the 21st century; next on my list is to go tubeless! My current rims are fine (mavic d521 rear/xc717 front) and I don't really want the expense of changing them for proper UST/tubeless ready rims. I'm currently running a pair of panaracer cinders 2.25, whilst they're pretty heavy, they grip well all round, have never punctured in the ten years they've been fitted and are just damn reliable; however they are pretty loose on the rims but I'm loathe to change them. Initially working on the front wheel only.... I've bought a roll of gorilla tape and some american classic tubeless presta valves, taped the rim up, added a strip of draught excluder into the bead well and taped over it again so it is almost a flat surface to the beads to sit/pressurise against. I can get the tyre to seat with a compressor but not a track pump, if I add another wrap of gorilla tape should I be able to do it with the pump? The bead is now pretty tight but I can still get the tyre on by hand without much hassle. The sidewall of the tyre is leaking where the logo has been printed on the carcass, I guess a wash of sealant over it should sort that out ok though. I picked up some OKO off road tyre sealant (intended for quads/farm vehicles etc) from a local engineers suppliers, 8 quid for 1250ml (beats 20 quid for less than a litre of stans and I have already got it to seal a test tyre no problems) but it is pretty thick, however it is water soluble so I intend to thin it down so it is the right consistency to flow round the carcass. What sort of consistency should I be looking for, would single cream be about right? The OKO sealant isn't latex based so doesn't dry up into a ball like stans can, hopefully it will still perform as intended when it has been watered down a little - planning on adding 80g ish of sealant mix (1:1 sealant/water). I will be carrying a tube with me till it has proved reliable though! Anyone got any suggestions or adivce on bodging this together? Edited May 25, 2013 by forteh Quote Link to comment Share on other sites More sharing options...
forteh Posted May 26, 2013 Author Report Share Posted May 26, 2013 Right, got the front tyre mounted and sealed in the bead. Unfortunately my decade old sidewalls are pretty porous and was foaming the lubricant mix, it has lost about 45 psi today but held tight otherwise. The sealant might not be sensitive enough to seal the leaks but I will try sloshing it around again later. Can porous sidewalls be cured easily? Quote Link to comment Share on other sites More sharing options...
trialsmax04 Posted May 26, 2013 Report Share Posted May 26, 2013 Porous sidewalls are really common on all tyres. I buy Specalized tubeless ready and there a little porous. The micro fibres in Stans seals them well so if the OKO stuff is similar then it should be fine. Just leave the wheel flat on its side for a few hours, then swap sides. Quote Link to comment Share on other sites More sharing options...
CurtisRider Posted May 26, 2013 Report Share Posted May 26, 2013 I can't decide whether to try tubeless or not, is it really worth the hassle? I rarely ever get a puncture and I hear stories of the tyres burping air on corners sometimes? Seems nearly as irritating... Quote Link to comment Share on other sites More sharing options...
forteh Posted May 26, 2013 Author Report Share Posted May 26, 2013 Porous sidewalls are really common on all tyres. I buy Specalized tubeless ready and there a little porous. The micro fibres in Stans seals them well so if the OKO stuff is similar then it should be fine. Just leave the wheel flat on its side for a few hours, then swap sides. I've read that about most non UST tyres, my panaracer cinders are a decade old now though so I suspect a bit of rubber perishing has occured. That said the majority of the sidewall bubbling/foaming seems to have dimished somewhat so hopefully the OKO is sealing it ok, just a case of getting the sealant to rest in the right places. From what I've read though, only the latex solutions like stans properly seal the sidewalls, the OKO is waterbased and not latex and might not; I will ring them on tuesday and see if they can provide the relevant info. They do a bike specific sealant (mine is intended of vehicular use and is much cheaper) but I don't know if the formulation is significantly different. If it isn't recommended for sealing the porous sidewalls then I will probably dismount the tyre, paint the inside sidewalls with liquid latex and try again I can't decide whether to try tubeless or not, is it really worth the hassle? I rarely ever get a puncture and I hear stories of the tyres burping air on corners sometimes? Seems nearly as irritating... I'm only trying it because: - A ) I can, for less than 30 quid outlay (£8 sealant, £7 gorilla tape, £10 tubeless valves) test a tubeless setup. I've never punctured the cinders (they are a heavy tyre to start with - about 800g) but I want to see how the different feel affects the bike. B ) I don't want to fork out a couple of hundred quid on a full on UST setup when mine is perfectly servicable if it can be converted - Also the challenge of doing something homebrewed appeals to me as an engineer From initial feel of my front wheel test, the tyre feels like its at a much higher pressure than it really is. The front XC717 rim is pretty narrow and below 40psi the 2.25 tyres squirm all over the place and feel rather unstable, at 30 psi on the tubeless setup it feels closer to 45-50 psi in there with a tube. I'm not sure how this will equate to in terms of handling/ride quality but it will be interesting to find out. With regards to the burping, I got the tyre mounted this morning and left it sealing (obviously not 100% yet), went to my parents with the fiance and kids for lunch and to install W7 on my mums pc (to get rid of the W8 pos on there), got back about 7 this evening and the tyre was really soft, I guess about 20 psi if that. As a test I tried to fold the tyre off the rim and burp it by forcing it sideways into the floor at 45°, the tyre folded almost completely underneath itself and not a single burp was given. As I would probably be running the tyres at double that pressure, I'm 100% confident about it not burping. That is using a heavy tyre with decent sidewalls and a wire bead though, I guess if you were to try the same test on a conti mountain king supersonic it might be a different story - I have that exact tyre on the front of the triton, perhaps I should test it tubeless Quote Link to comment Share on other sites More sharing options...
Tomm Posted May 26, 2013 Report Share Posted May 26, 2013 Sounds like you're doing the right things. Some thoughts in no particular order: Don't expect it to all work with just a track pump - if you've got access to a compressor then use it! Otherwise, make one of these. Inflate with the compressor, then remove the valve core and pour in the sealant. They should go back up with just a track pump (the bead usually stays sealed if you don't manipulate it too much). Even on tubeless-ready tyres, the sidewalls still leak a bit initially. Just top them up with fluid, pump up to 40 psi and wait or... Top tip - going for a ride usually fixes tubeless issues (I guess it sloshes the fluid around a good bit). No idea about OKO sealant, but Stans is labelled as suitable for cars / motorbikes / lorries etc as well as push bikes. Single cream consistency sounds about right, maybe slightly thinner. I carry a tube with me anyway - even though my tubeless setup is leak-free and reliable, you can still pinch... Quote Link to comment Share on other sites More sharing options...
CurtisRider Posted May 26, 2013 Report Share Posted May 26, 2013 Just found some new Schwalbe 20" BMX tubes (the threaded valve body ones) so I shall order some Stans sealant and give it a go this week. I only have standard wire bead Rubber Queens currently but they have been good enough on the trails so far and I cant really afford to be spending serious money on new tyres. Will I get away with using one of those 12V car air compressors or will I be needing to wait and use my proper one at home? Quote Link to comment Share on other sites More sharing options...
forteh Posted May 26, 2013 Author Report Share Posted May 26, 2013 I almost got it with the track pump, I know UST are supposed to be inflatable by hand but I had to use a borrowed compressor to get this seated. I have a small compressor for my airbrush but I don't think it will be man enough to blow these baggy as hell panaracers onto the rims, tighter tyres perhaps but not these! As you said the bead should be sealed with the sealant and should hold with carefull handling when flat. I have the tyre sitting at 50 psi at the moment, I should probably drop that to get the sealant to hold - the bike specific OKO instructions for tubeless installations say to keep it below 45 psi for sealing purposes. I'm hoping to get over cannock chase tomorrow so perhaps that will help with some of the sidewall issues. The OKO stuff I have is intended for more agricultural stuff and says on the bottle "not for more than 50 kph", as long as it seals all the holes I don't care what speed! Mixed at 1:1 ratio is was actually more like double cream, it has still sealed 95% of the tyre and there is still a noticeable puddle of it in there. A tube will be carried till I know it's reliable, pinching over cannock chase isn't really likely to happen Quote Link to comment Share on other sites More sharing options...
forteh Posted May 26, 2013 Author Report Share Posted May 26, 2013 I belive if you use the split 20" tube method you don't need anywhere near as much pressure to seal the bead, however it's volume of air rather than pressure that gets them to seat. In theory a good rim/bead seal (UST) will blow on dry and pretty much seal without sealant, however with the xc717 and 2.25 cinder I had to physically build up the inner seal surface (initial wrap of gorilla tape to seal spoke holes, wrap of foam draught excluder to build up the bead/nipple head well and another two wraps of tape over the top) to get it to inflate. The bead needs to be tight on the rim, I needed to use a tyre lever to get the bead into place and could probably got another wrap on there before fitting the tyre became impossible - it may well be that with the third wrap of tape it would have popped on with the track pump. I don't think a 12v compressor will do the job, it's like trying to pump a tyre with a shock pump - the volume of air you're moving just isn't great enough. I was using a compressor with a decent size tank, the regulator was wound up to 80 psi and still took a bit of work to get it to seal (see above comment regarding baggy tyres). I have read that the rubber queen sidewalls are really porous, might be worth painting them with latex (far cheaper than stans) beforehand and leaving to dry before trying to mount them tubeless. Quote Link to comment Share on other sites More sharing options...
CurtisRider Posted May 27, 2013 Report Share Posted May 27, 2013 Cheers for your help! I'll make a ghetto bottle inflator thing and hope for the best! My tyres are already very tight to fit (the rim tape i have is same sort of thickness as a tube) so I should have reasonable luck with getting the bead sealed. Any idea what kinds of chain shops sell liquid latex? I'm assuming art shops will sell it but haven't really noticed any in Nottingham... Quote Link to comment Share on other sites More sharing options...
forteh Posted May 27, 2013 Author Report Share Posted May 27, 2013 Sounds as though you might be ok with the queens then for seating, try it and see if the sidewalls will seal. Tyre sealant isn't just latex, they have various additives to slow curing time and lumps in there to plug holes. Have a look at home brew sealants, people use mould builder latex with some slime and a bit of antifreeze to keep it all liquid, chuck some glitter of various sizes for hole plugging and you're set. Hobbycraft would be your best place to buy all of those ingredients apart from the slime. Alternatively by some stan's or similar. My build has held air overnight, pressure has dropped from 40 down to 25 but it's only foaming around where three logo is printed on, hopefully a blast around Cannock later will help, perhaps a squeeze more sealant will do the trick. Quote Link to comment Share on other sites More sharing options...
forteh Posted May 27, 2013 Author Report Share Posted May 27, 2013 Have added about 30ml of latex into the tyre and that seems to be holding the sidewalls at 40 psi ok, above 50 and it still foams slightly but much less that before, I guess that riding it will start to get a proper coat in there Watered the latex down to the consistency of milk our there about. Quote Link to comment Share on other sites More sharing options...
Tomm Posted May 27, 2013 Report Share Posted May 27, 2013 I don't think a 12v compressor will do the job, it's like trying to pump a tyre with a shock pump - the volume of air you're moving just isn't great enough. I can confirm that this is indeed true. You can pump more volume with a track pump. Ghetto bottle thing *** though. You shouldn't really put more than 40psi in tubeless. They can pop off the rims at high pressures, allegedly. Quote Link to comment Share on other sites More sharing options...
forteh Posted May 28, 2013 Author Report Share Posted May 28, 2013 (edited) Well it has bubbled through the sidewalls a little overnight, a bit of foaming and damp patches where the logos are printed, guess it has affected the porosity local to that area because no where else is visibly weeping. When I try to mount the rear tyre I will paint the insides with latex and let that set beforehand to see if that helps. I think that I'm fighting a losing battle with these panaracers, with the tyre deflated I can't get it to reinflate by hand, needed to use the compressor but it didn't take much to get it on - that said a 2l ghetto bottle compressor wouldn't have the volume either. I might try mounting my larsen tt on the back (would probably roll a bit better as well) if the bead is a bit tighter and see if that will pump by hand. edit: I have emailed OKO regarding sealing the sidewalls, see what they come back with. It's possible that there just isn't enough sealant in there full stop, I put in 100ml of the mix (50ml sealant, 50ml water) and whilst it is still sloshing around inside I guess it might just be water and all the sealant has been used up plugging the holes so far. Maybe I should just try putting 100ml of the sealant in neat (although it is very viscous) and see if that is any better. Edited May 28, 2013 by forteh Quote Link to comment Share on other sites More sharing options...
Tomm Posted May 28, 2013 Report Share Posted May 28, 2013 I wouldn't get too upset if you can't mount with a track pump - I can't mount my dedicated tubeless tyres (Hans Dampf) on my dedicated rims (Stans Flow). The bottle thing helps loads though. Use a 3l bottle for more volume. Quote Link to comment Share on other sites More sharing options...
forteh Posted May 28, 2013 Author Report Share Posted May 28, 2013 Ah that's reassuring then, it's been damn close at times and I reckon with a couple more wraps of tape it would go. Had a response from OKO and whilst they can't endorse thinning the sealant down (certainly not 1:1 like I did) it can be done and indeed their cycle sealant is the same stuff, just a bit thinner. They also recommended 120ml in a 26" tyre, bearing in mind I have only actually got 50ml in there at the moment then and it still sealed! I will try putting 100ml sealant with 20ml water to thin it down a bit and hopefully it will hold the sidewalls better The OKO stuff doesn't dry out like latex based ones do so it's basically maintenance free once in there. Would thoroughly recommend their products though, been making tyre sealants for 28 years and used for all sorts of stuff from military, to mining, to HGVs - well worth a look I reckon http://www.oko.com. Quote Link to comment Share on other sites More sharing options...
forteh Posted May 29, 2013 Author Report Share Posted May 29, 2013 I've mounted the maxxis larsen tt on the rear wheel and it is much tighter on the bead, won't quite inflate by hand but has sealed really well on the bead, the sidewalls don't seem to be leaking either. However there is a leak some where on the tape because it's blowing air out past the valve/nipples - I have to strip the while thing down and start again Quote Link to comment Share on other sites More sharing options...
CurtisRider Posted May 29, 2013 Report Share Posted May 29, 2013 I started on mine today, the tyre is tight fitting yet there is air escaping near the valve when quickly trying it with a hand pump. I'm assuming it's just cos it needs a bloody good blast of air to pop it all outwards? Quote Link to comment Share on other sites More sharing options...
forteh Posted May 29, 2013 Author Report Share Posted May 29, 2013 Brush heavily soaped water round the rim/bead and get a compressor on it, helps lubricate and create an initial seal. Once the bead has blown out, start shaking the sealant about inside the tyre and keep brushing the soap round the rim till you have sealed all the bubbles Quote Link to comment Share on other sites More sharing options...
forteh Posted May 30, 2013 Author Report Share Posted May 30, 2013 Stripped the rear wheel tonight, degreased and re-taped the rim, mounted the tyre and still leaking in the same place! Took the valve stem out and fiddled around with the o-rings, still no joy. Eventually I cut the gorilla tape around the valve hole so it was a perfect circular cut (rather than the cross cut in the tape which is the normal method and worked on the front wheel), retightened the valve, inflated and it seems to be solid. Annoying because I don't think I actually needed to strip the tape, just tidy up the valve hole a bit. Ran a bath of cold water and checked the wheel inch by inch for bubbles and there doesn't seem to be any so fingers crossed Having said that I will probably go downstairs to flat tyres knowing my luck! They're sitting pumped up to 40psi, will check the pressure in the morning and ride to work if it's dry enough. For reference, the OKO off road sealant works a treat, 100ml of sealant works spot on, 8 quid for 1250ml of sealant pisses all over 20 quid for 950g of stans that needs to be topped up every few months. Not tested punctures yet as I'm loathe to pierce/damage the tyre carcass just to find out if it seals or not! Quote Link to comment Share on other sites More sharing options...
dezmtber Posted May 31, 2013 Report Share Posted May 31, 2013 That oko sounds good stuff. When I used to usr atomlab pimplites on maxxis exo tyres I used a co2 canister to get them to seat on the rim. Works better than the homemade bottle. Just don't fill the Tyre with the valve at the bottom as you can freeze the Stans That oko sounds good stuff. When I used to usr atomlab pimplites on maxxis exo tyres I used a co2 canister to get them to seat on the rim. Works better than the homemade bottle. Just don't fill the Tyre with the valve at the bottom as you can freeze the Stans Quote Link to comment Share on other sites More sharing options...
forteh Posted May 31, 2013 Author Report Share Posted May 31, 2013 The rear is now mounted with the larsen TT and held most of its pressure overnight, it has bled a little through the sidewalls but no where near as much as the front panaracer did; hopefully given enough time the sealant will work its way round and seal them up, failing that I might add a syringe of latex in there like I did with the front one. Front tyre lost 3psi overnight, rear tyre lost 15psi Quote Link to comment Share on other sites More sharing options...
Tomm Posted June 5, 2013 Report Share Posted June 5, 2013 Yeah, if they seal up for > 10 minutes, eventually they will completely seal (with sealant). Quote Link to comment Share on other sites More sharing options...
forteh Posted June 14, 2013 Author Report Share Posted June 14, 2013 Well the original mount of the rear wheel failed after a couple of days, held pressure like a boss and then lost it all over night Traced the leak to the valve stem and no matter what combination of tape, sealant and o-rings it just wouldn't seal like the front one had. After a couple of hours of frustration trying to sort it I gave up and put a tube back in till I could be bothered again. Had another play with it last night and I think I have a better chance of keeping it sealed this time.... The american classic valve stems I'm using are presta fitment and my rims are shrader, obviously there is 3mm difference in the diameters but the front one sealed up without a problem, I guess the hole on the rear rim is just slightly larger than the front one and it stopped it sealing properly with the o-ring. I got some M6 stainless washers from work to glue inside the rim and give a better seat for the o-ring to seal against. Stripped the rear wheel down, mixed up a batch of 2 part polyurethane adhesive and glued a washer into place, let it cure and filed the adhesive down so the o-ring would be sealing against the washer itself. Put it all back together, put 120ml of the neat OKO sealant in the tyre, spun the tyre round the rim a few times to distribute the sealant onto the bead and it pumped up by hand with minimal effort Shook the sealant around to get the bead 100% airtight and it was all good, except the f#@cking valve stem is still leaking! Unmounted the tyre, took the valve out, cleaned it all up and tried layering more gorilla tape over the valve area, rebuilt it all and it's identical! There are no other ways that air can be getting through the rim except past the stem o-ring and that is sealing against a fitted flat surface so I'm now just about to sack off the idea altogether. Took the tyre off again and started to peel the tape off (starting with the additional layers I had put over the glued washer) and the washer is loose! The adhesive had bonded to the rim but not the washer, it had formed a nice tight circular seat for it though; dropped a spot of cyanoacrylate in there and reseated the washer. Rebuilt the wheel again, pumped up and it held pressure overnight, it's not leaking through the valve stem and all being well shouldn't fail now Quote Link to comment Share on other sites More sharing options...
isitafox Posted June 14, 2013 Report Share Posted June 14, 2013 I admire your patience at constantly stripping the wheel, even when I get a puncture on my bike I refuse to take the wheel out as I can't be bothered! Quote Link to comment Share on other sites More sharing options...
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